NCC 2016 Volume Two
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Part 3.8.6 Sound Insulation

Part 3.8.6 Sound Insulation

Appropriate Performance Requirements

Appropriate Performance Requirements:

Where an alternative sound insulation system is proposed as a Performance Solution to that described in Part 3.8.6, that proposal must comply with—

  1. P2.4.6; and
  2. the relevant Performance Requirements determined in accordance with 1.0.7.

3.8.6.1 Application

Compliance with this acceptable construction practice satisfies Performance Requirement for sound insulation.

3.8.6.2 Sound insulation requirements

(a)

To provide insulation from airborne and impact sound, a separating wall between two or more Class 1 buildings must—

(i)

achieve the weighted sound reduction index with spectrum adaptation term (Rw + Ctr) and discontinuous construction requirements, as required by Table 3.8.6.1; and

(ii)

be installed in accordance with the appropriate requirements of 3.8.6.3 and 3.8.6.4.

(b)

For the purpose of this Part, the Rw + Ctr must be determined in accordance with AS/NZS 1276.1 or ISO 717.1, using results from laboratory measurements.

Table 3.8.6.1 REQUIRED Rw AIRBORNE AND IMPACT SOUND LEVELS FOR SEPARATING WALLS

SEPARATING WALL — LOCATION AND PENETRATIONS DISCONTINUOUS CONSTRUCTION REQUIRED Rw+Ctr (As per Table 3.8.6.2)
Between a bathroom, sanitary compartment, laundry or kitchen and a habitable room (other than a kitchen) in an adjoining Class 1 building (dwelling) (see Figure 3.8.6.1). YES 50
In all other cases to those listed above (See Figure 3.8.6.1). NO 50

DUCT, SOIL, WASTE, AND WATER SUPPLY PIPES AND STORM WATER PIPES

A duct, soil, waste, or water supply pipe or storm water pipe that passes through a separating wall between Class 1 buildings—

(a) if the adjacent room is a habitable room (other than a kitchen); or

 NO 40

(b) if the room is a kitchen or any other room.

 NO 25

Notes:

  1. Discontinuous construction means a wall system having a minimum 20 mm cavity between two separate leaves, with—
    1. for masonry, where wall ties are required to connect leaves, the ties are of the resilient type; and
    2. for other than masonry, there is no mechanical linkage between leaves except at the periphery.
  2. A staggered stud wall is not deemed to be discontinuous construction.

Figure 3.8.6.1

REQUIRED AIRBORNE AND IMPACT SOUND INSULATION — PLAN VIEW

v2_Fig3861_2005.svg

3.8.6.3 General installation requirements for walls

(a)

To achieve the appropriate level of sound insulation, walls must—

(i)

be constructed in accordance with the appropriate requirements contained in (b) to (f); and

(ii)

at the junction of sound insulated walls with any perimeter walls and roof cladding, be sealed in accordance with Figure 3.8.6.2.

Figure 3.8.6.2

SOUND INSULATION BETWEEN BUILDINGS - STAGGERED STUD WALL CONFIGURATION

v2_Fig3862_2009.svg
(b)

Masonry units must be laid with all joints filled solid, except for adequately sound insulated articulation joints, including those between the masonry and any adjoining construction.

(c)

Concrete panels must have joints between panels and any adjoining construction filled solid.

(d)

Plasterboard must be installed as follows:

(i)

If one layer is required on both sides of a wall the joints must be staggered on opposite sides (See Figure 3.8.6.3).

(ii)

If two layers are required, the first layer must be fastened in accordance with (i) and the second layer joints must not coincide with those of the first layer (See Figure 3.8.6.3).

(iii)

The following joints must be taped and filled solid:

(A)

Outer layer joints between sheets.

(B)

Joints between sheets and any adjoining construction.

Figure 3.8.6.3

TYPICAL INSTALLATION OF PLASTER SHEETS FOR SOUND INSULATION

v2_Fig3862sv_2005.svg
(e)

Steel framing and perimeter members must be installed as follows:

(i)

The section of steel must be not less than 0.6 mm thick.

(ii)

Studs must be not less than 63 mm in depth unless another depth is specified in Table 3.8.6.2.

(iii)

Studs must be fixed to steel top and bottom plates of sufficient depth to permit secure fixing of the plasterboard.

(iv)

All steel members at the perimeter of the wall must be securely fixed to the adjoining structure and bedded in resilient compound or the joints must be caulked so that there are no voids between the steel members and the wall.

(f)

Timber studs and perimeter members must be installed as follows:

(i)

Studs must be fixed to top and bottom plates of sufficient depth to permit secure fixing of the plasterboard.

(ii)

Noggings and like members must not bridge between studs supporting different wall leaves.

(iii)

All timber members at the perimeter of the wall must be securely fixed to the adjoining structure and bedded in resilient compound or the joints must be caulked so there are no voids between the timber members and the wall.

3.8.6.4 Services

(a)

Services must not be chased into concrete or masonry separating walls.

(b)

If a duct, soil, waste, water supply or storm water pipe serves or passes through a separating wall or is located in a separating wall—

(i)

a door or panel providing access to a duct or pipe required to be separated must—

(A)

not open into any habitable room, other than a kitchen; and

(B)

in any other part must be firmly fixed so as to overlap the frame or rebate of the frame by not less than 10 mm and be constructed of—

(aa)

wood, plasterboard or blockboard not less than 33 mm thick; or

(bb)

compressed fibre reinforced cement sheeting not less than 9 mm thick; or

(cc)

other suitable material with a mass per unit area not less than 24.4 kg/m2; and

(ii)

in the case of a water supply pipe, it must—

(A)

only be installed in discontinuous construction; and

(B)

in the case of a water supply pipe that serves one dwelling, not be fixed to the wall leaf on the side of any other dwelling and have a clearance not less than 10 mm to the other wall leaf.

(c)

Electrical outlets must be offset from each other—

(i)

in masonry walling, not less than 100 mm; and

(ii)

in timber or steel framed walling, not less than 300 mm.

Table 3.8.6.2 ACCEPTABLE FORMS OF CONSTRUCTION

Description R w + C tr (not less than) Construction
Wall construction type: Masonry

Two leaves of 110 mm clay brick masonry with—

  1. cavity not less than 50 mm between leaves; and
  2. 50 mm thick glass wool insulation with a density of 11 kg/m3 or 50 mm thick polyester insulation with a density of 20 kg/m3 in the cavity.
 50
v2_Tab386201_2005.svg

Two leaves of 110 mm clay brick masonry with—

  1. cavity not less than 50 mm between leaves; and
  2. 13 mm cement render on each outside face.
 50
v2_Tab386202_2005.svg

Single leaf of 110 mm clay brick masonry with—

  1. a row of 70 mm x 35 mm timber studs or 64 mm steel studs at 600 mm centres, spaced 20 mm from the masonry wall; and
  2. 50 mm thick mineral insulation or glass wool insulation with a density of 11 kg/m3 positioned between studs; and
  3. one layer of 13 mm plasterboard fixed to outside face of studs and outside face of masonry.
 50
v2_Tab386203_2005.svg

Single leaf of 90 mm clay brick masonry with—

  1. a row of 70 mm x 35 mm timber studs or 64 mm steels studs at 600 mm centres, spaced 20 mm from each face of the masonry wall; and
  2. 50 mm thick mineral insulation or glass wool insulation with a density of 11 kg/m3 positioned between studs in each row; and
  3. one layer of 13 mm plasterboard fixed to studs on each outside face.
 50
v2_Tab386204_2005.svg
Single leaf of 220 mm brick masonry with 13 mm cement render on each face. 50
v2_Tab386205_2005.svg
Wall construction type: Concrete
150 mm thick plain off form concrete. 50
v2_Tab386206_2005.svg
200 mm thick concrete panel with one layer of 13 mm plasterboard or 13 mm cement render on each face. 50
v2_Tab386207_2005.svg

100 mm thick concrete panel with—

  1. a row of 64 mm steel studs at 600 mm centres, spaced 25 mm from the concrete panel; and
  2. 80 mm thick polyester insulation or 50 mm thick glass wool insulation with a density of 11 kg/m3, positioned between studs; and
  3. two layers of 13 mm plasterboard fixed to outside face of studs and one layer of 13 mm plasterboard fixed to outside face of concrete panel.
 50
v2_Tab386208_2005.svg

125 mm thick concrete panel with—

  1. a row of 64 mm steel studs at 600 mm centres, spaced 20 mm from the concrete panel; and
  2. 70 mm polyester insulation with a density of 9 kg/m3, positioned between studs; and
  3. one layer of 13 mm plasterboard fixed to the outside face of the studs.
 50
v2_Tab386209_2005.svg
Wall construction type: Autoclaved aerated concrete

75 mm thick autoclaved aerated concrete wall panel with—

  1. a row of 64 mm steel studs at 600 mm centres, spaced 20 mm from the autoclaved aerated concrete wall panel; and
  2. 75 mm thick glass wool insulation with a density of 11 kg/m3 positioned between studs; and
  3. one layer of 10 mm moisture resistant plasterboard or 13 mm fire protective grade plasterboard fixed to outside face of studs and outside face of autoclaved aerated concrete wall panel.
 50
v2_Tab386210_2005.svg

75 mm thick autoclaved aerated concrete wall panel with—

  1. a row of 64 mm steel studs at 600 mm centres, spaced 35 mm from the autoclaved aerated concrete panel wall; and
  2. 28 mm metal furring channels fixed to the outside face of the autoclaved aerated concrete wall panel, with 50 mm thick polyester insulation with a density of 9 kg/m3 positioned between furring channels and one layer of 13 mm fire protective grade plasterboard fixed to furring channels; and
  3. 105 mm thick glass wool insulation with a density of 7 kg/m3 positioned between studs; and
  4. one layer of 13 mm fire protective grade plasterboard fixed to the outside face of the studs.
 50
v2_Tab386211_2005.svg

Two leaves of 75 mm autoclaved aerated concrete wall panel with—

  1. a cavity not less than 30 mm between panels containing 50 mm glass wool insulation with a density of 11 kg/m3; and
  2. one layer of 10 mm plasterboard fixed to outside face of each panel.
 50
v2_Tab386212_2005.svg
Wall construction type: Timber and steel framing

Two rows of 90 x 35 mm timber studs or two rows of 64 mm steels studs at 600 mm centres with—

  1. an air gap not less than 20 mm between the rows of studs; and
  2. 50 mm thick glass wool insulation or 60 mm thick polyester insulation with a density of 11 kg/m3; positioned between one row of studs, and
  3. two layers of 13 mm fire protective grade plasterboard or one layer of 6 mm fibre cement sheet and one layer of 13 mm fire protective grade plasterboard, fixed to outside face of studs.
 50
v2_Tab386213_2005.svg

Two rows of 64 mm steel studs at 600 mm centres with—

  1. an air gap not less than 80 mm between the rows of studs; and
  2. 200 mm thick polyester insulation with a density of 14 kg/m3; positioned between studs; and
  3. one layer of 13 mm fire-protective grade plasterboard and one layer 13 mm plasterboard on one outside face and one layer of 13 mm fire-protective grade plasterboard on the other outside face.
 50
v2_Tab386214_2005.svg

Explanatory information

Explanatory information:

The wall configurations shown in Table 3.8.6.2 are typical examples. Other proprietary methods are available for meeting the Rw + Ctr requirements of 3.8.6.2.

STATE AND TERRITORY VARIATIONS

STATE AND TERRITORY VARIATIONS

In Northern Territory Part 3.8.6 acceptable construction practice is replaced with the following:

Acceptable construction practice

3.8.6.1 Application

Compliance with this Part satisfies Performance RequirementP2.4.6 for sound insulation.

3.8.6.2 Sound insulation requirements
(a)

A separating wall between two or more Class 1 buildings must—

(i)

achieve the weighted sound reduction index (Rw) and impact sound resistance required by Table 3.8.6.1; and

(ii)

be installed in accordance with the appropriate requirements of 3.8.6.3 and 3.8.6.4; and

(b)

for the purpose of this Part, the Rw may be determined in accordance with AS/NZS 1276.1 or ISO 717.1.

Table 3.8.6.1 REQUIREDw AND SOUND IMPACT LEVELS FOR SEPARATING WALLS

SEPARATING WALL—LOCATION AND PENETRATIONS IMPACT SOUND RESISTANCE (As per Table 3.8.6.2 ) R w (As per Table 3.8.6.3 )

TYPE A

Between a bathroom, sanitary compartment, laundry or kitchen and a habitable room (other than a kitchen) in an adjoining Class 1 building (dwelling) (see Figure 3.8.6.1).

 YES 50

TYPE B

In all other cases to those listed as Type A. (See Figure 3.8.6.1)

 NO 45

SOIL AND WASTE PIPES

A waste pipe or other penetration that serves or passes through a separating wall between houses—

  1. If the adjacent room is a habitable room (other than a kitchen); or
  2. If the room is a kitchen or any other room.

NO
NO

45
30

Figure 3.8.6.1

REQUIRED Rw — PLAN VIEW

v2_Fig3861sv_2005.svg
3.8.6.3 General installation requirements for walls
(a)

To achieve the appropriate Rw and impact sound resistance, walls must—

(i)

be installed in accordance with the appropriate requirements contained in b to f; and

(ii)

at the junction of sound insulated walls with perimeter walls and roof cladding, be sealed in accordance with any relevant detail in Figure 3.8.6.3.

(b)

Masonry units must—

(i)

be laid with all joints filled solid, including those between the masonry and any adjoining construction; and

(ii)

not be chased for services.

(c)

Joints between concrete slabs, wall units and any adjoining construction must be filled solid.

(d)

Plasterboard must be installed as follows:

(i)

If one layer is required under this Part, joints must be staggered with the joints in sheets on the opposite face of the wall.

(ii)

If 2 layers are required, the first layer must be fixed according to (i) and the second layer must be fixed to the first layer with nails, screws or adhesive so that the joints do not coincide with those of the first layer.

(iii)

Joints between sheets or between sheets and any adjoining construction must be taped and filled solid.

(iv)

Fire-protective grade plasterboard (when nominated) must be the grade manufactured for use in fire-resisting construction.

Figure 3.8.6.2

TYPICAL INSTALLATION OF PLASTER SHEETS FOR SOUND INSULATION

v2_Fig3862sv_2005.svg
(e)

Steel studs and perimeter members must be installed as follows:

(i)

The section of steel must be not less than 0.6 mm thick.

(ii)

Studs must be not less than 63 mm in depth unless another depth is specified in the Table.

(iii)

Studs must be fixed to steel top and bottom plates of sufficient depth to permit secure fixing of the plasterboard.

(iv)

All steel members at the perimeter of the wall must be securely fixed to the adjoining structure and bedded in resilient compound or the joints must be caulked so that there are no voids between the steel members and the wall.

(f)

Timber studs and perimeter members must be installed as follows:

(i)

Studs must be fixed to top and bottom plates of sufficient depth to permit secure fixing of the plasterboard.

(ii)

Noggings and like members must not bridge between studs supporting different wall leaves.

(iii)

All timber members at the perimeter of the wall must be securely fixed to the adjoining structure and bedded in resilient compound or the joints must be caulked so there are no voids between the timber members and the wall.

3.8.6.4 Soil and waste pipes

If a soil or waste pipe passes through a separating wall—

(a)

a door or panel providing access to the pipe must not open into any habitable room, other than a kitchen; and

(b)

an access door or panel in any other part must be firmly fixed so as to overlap the frame or rebate of the frame by not less than 10 mm, be fitted with a sealing gasket along all edges and constructed of—

(i)

wood, plasterboard or blockboard not less than 38 mm thick; or

(ii)

compressed fibre reinforced cement sheeting not less than 9 mm thick; or

(iii)

other suitable material with a mass per unit area not less than 24.4 kg/m2.

Explanatory information

Explanatory information:

The wall configurations shown in Tables 3.8.6.2 and 3.8.6.3 are typical examples. Other proprietary methods are available for meeting the Rw and sound impact levels required by Table 3.8.6.1.

Table 3.8.6.2

Table 3.8.6.2
CONSTRUCTION OF WALLS TO:

(A) REDUCE IMPACT SOUND; AND

(B) ACHIEVE A 50 Rw

WALL CONSTRUCTION TYPE DESIGN DIAGRAM — PLAN VIEW

CAVITY BRICKWORK

2 leaves 90 mm brick masonry with—

  1. all joints filled solid with mortar; and
  2. an air space not less than 40 mm between the leaves; and
  3. the leaves connected only by ties in accordance with AS 3700 and wall tie spacing details as set out in Part 3.3.
v2_Tab3862asv_2005.svg

SINGLE LEAF BRICKWORK

80 mm thick brick masonry with—

  1. each face rendered 13 mm thick; and
  2. 50x12 mm thick timber battens at not more than 610 mm centres fixed to each face but not recessed into the render; and
  3. one layer of 12 mm thick softboard nailed to the battens; and
  4. 6 mm thick medium density hardboard adhesive-fixed to the softboard.
v2_Tab3862bsv_2005.svg

CONCRETE BLOCKWORK

190 mm thick concrete block masonry with—

  1. each face of the blocks fitted with 50x50 mm timber battens, spaced at not more than 610 mm centres, screw-fixed into resilient plugs with rubber inserts; and
  2. the space between the battens completely filled with mineral or glass wool blanket or batts not less than 50 mm thick; and
  3. the outer face of the battens finished with plasterboard not less than 10 mm thick.
v2_Tab3862csv_2005.svg

TIMBER FRAMED WALLING

70 x 45 mm F5 staggered timber studs at 600 mm centres both sides on 120x35 mm F5 timber plates with—

  1. one layer of 16 mm fire protective grade plasterboard on both faces; and
  2. 50 mm glass fibre batts.
v2_Tab3862dsv_2005.svg

TIMBER FRAMED WALLING

70 x 45 mm F5 timber double studs at 450 – 600 mm centres with an air space not less than 20 mm between studs with two layers of 13 mm fire protective grade plasterboard on both faces.
v2_Tab3862esv_2005.svg

STEEL STUD WALLING

64 mm staggered metal studs (0.75 mm base metal thickness) at 600 mm centres both sides, clipped in 92 mm metal tracks with—

  1. two layers of 13 mm fire protective grade plasterboard to each side; and
  2. 50 mm glasswool cavity batts.
v2_Tab3862fsv_2005.svg

STEEL STUD WALLING

64 mm double metal studs (0.75 mm base metal thickness) at 600 mm centres with an air space not less than 20 mm between studs, in separate frames with no mechanical links with—

  1. two layers of 13 mm fire protective grade plasterboard to each side; and
  2. 50 mm glasswool cavity batts.
v2_Tab3862gsv_2005.svg

Table 3.8.6.3

Rw APPLICABLE TO CONSTRUCTION

WALL CONSTRUCTION TYPE Rw DESIGN DIAGRAM — PLAN VIEW
CLAY BRICKWORK
  1. 110 mm thick in one or more leaves and with a mass per unit area of not less than 290 kg/m2.
 45
v2_Tab3863Asv_2005.svg
  1. 80 mm thick, pressed brick and rendered 13 mm on one side, the mass per unit area of the unrendered wall being not less than 215 kg/m2.
 45
v2_Tab3863Bsv_2005.svg
CALCIUM SILICATE BRICKWORK
  1. 90 mm thick calcium silicate brick with one layer of 10 mm fire protective grade plasterboard on each side.
 45
v2_Tab3863Csv_2005.svg
  1. 90 mm thick calcium silicate brick with one layer of 10 mm fire protective plasterboard and one layer of fire protective plasterboard on metal furring channels.
 45
v2_Tab3863Dsv_2005.svg
CONCRETE BLOCKWORK
  1. 190 mm solid units (or thicker)

Material density 2200 kg/m3

 45
v2_Tab3863Esv_2005.svg
  1. 110 mm solid units (or thicker)

Material density 2200 kg/m3

Material thickness — 83 mm min.

10 mm plasterboard or 12 mm render on each face.

 45
v2_Tab3863Fsv_2005.svg
CONCRETE WALL

In-situ concrete — 125 mm thick and with a density of not less than 2200 kg/m3.

 45
v2_Tab3863Gsv_2005.svg
STEEL STUD WALLING
  1. With 2 layers of 16 mm thick fire-protective grade plasterboard fixed to each face.
 45
v2_Tab3863Hsv_2005.svg
  1. With 2 layers of 13 mm plasterboard on both sides of 75 mm studs.
 45
v2_Tab3863Isv_2005.svg
TIMBER STUD WALLING

70 x 45 mm timber studs at 450 – 600 mm centres with

  1. one layer of 16 mm fire protective grade plasterboard on one face; and
  2. 50 mm glass fibre batts; and
  3. one layer of 16 mm fire protective grade plasterboard on metal resilient channel.
 49
v2_Tab3863Jsv_2005.svg

70 x 45 mm timber studs at 450 – 600 mm centres with two layers of 16 mm fire protective grade plasterboard on both sides.

 46
v2_Tab3863Ksv_2005.svg
DUCTS OR OTHER CONSTRUCTION SEPARATING SOIL AND WASTE PIPES FROM UNITS
MASONRY

Not less than 90 mm thick.

 30
v2_Tab3863Lsv_2005.svg
PLASTERBOARD
  1. 2 layers of plasterboard each 10 mm thick, fixed to timber studs not less than 75x50 mm and spaced at not more than 400 mm centres.
 30
v2_Tab3863Msv_2005.svg
  1. 2 layers of plasterboard each 13 mm thick, one on each side of steel studs not less than 50 mm deep and spaced at not more than 400 mm centres.
 30
v2_Tab3863Nsv_2005.svg

Figure 3.8.6.3

SOUND INSULATION BETWEEN UNITS — DOUBLE STUD WALL CONFIGURATION

v2_Fig3863sv_2009.svg